import java.util.*;
 class Example2_5 {
  public static void main(String args[]) {
   int start=0,end,middle;
   int a[]={20175316,45,67,89,123,-45,67};
   int N=a.length;
   for(int i=0;i<N;i++){
       for(int j=i+1;j<N;j++){
    if(a[j]<a[i]){
     int t =a[j];
     a[j] = a[i];
     a[i] =t;
     }
    }
   }
   System.out.println(Arrays. toString(a));
   Scanner scanner = new Scanner(System.in);
   System.out.println("输入整数，程序判断改整数是否在数组中:");
   int number=scanner.nextInt();
   int count =0;
   end =N;
   middle=(start+end)/2;
   while(number!=a[middle]){
    if(number>a[middle])
     start=middle;
    else if(number<a[middle])
     end=middle;
    middle=(start+end)/2;
    count++;
    if(count>N/2)
     break;
    }
    if(count>N/2)
     System.out.printf("%d不在数组中.\n",number);
    else
     System.out.printf("%d在数组中.\n",number);
}
}
